This invention relates to apparatus for coating parts and more particularly to apparatus for spray painting parts.
Most parts in modern industrial equipment require some manner of coating or painting to optimize the appearance of the part and/or to protect the part. Many techniques are available for painting parts. Whereas the many available techniques are generally satisfactory for painting parts having only exterior surfaces to be painted or having interior surfaces that are simple and readily accessible, none in of the prior art painting techniques provide smooth, even, consistent coating with respect to all surfaces on an intricate part including intricate blind interior surfaces.
This invention is directed to the provision of an improved painting apparatus.
More specifically, this invention is directed to the provision of an improved painting apparatus whereby a smooth, even coating may be consistently and uniformly applied even to intricate interior surfaces.
The painting apparatus of the invention comprises a main rack assembly mounted for rotation about a central axis; a plurality of rack subassemblies carried by the main rack assembly and mounted for respective rotation about a plurality of subassembly axes spaced circumferentially about and parallel to the central axis; a plurality of part holder devices provided on each rack subassembly at spaced locations along the respective subassembly axis; and drive means operate to spin the main rack about the central axis while simultaneously spinning each of the rack subassemblies about their respective subassembly axes. This compound rotation of the parts to be painted, about both the central axis of the main rack assembly and simultaneously about the axis of the respective rack subassembly, has been found to be effective to apply smooth uniform, even coating even to a part having an intricate interior surface configuration.
According to a further feature of the invention, the main rack assembly comprises a central vertical shaft mounted for rotation about the central axis, an upper support structure proximate an upper end of the shaft, and a lower support structure proximate a lower end of the shaft; and each rack subassembly includes a vertical part support structure journaled at an upper end thereof in the upper support structure, journaled at a lower end thereof in the lower support structure, and mounting the part holder devices intermediate the upper and lower ends thereof. This specific rack construction facilitates the provision of the compound rotation of the part.
According to a further feature of the invention, the drive means includes primary drive means operate to spin the vertical shaft about the central axis and secondary drive means operative to spin the vertical part support structures about the subassembly axes, and the secondary drive means are driven by the primary drive means via the spinning of the vertical shaft. This specific drive arrangement simplifies the drive of the rack assembly and rack subassemblies.
According to a further feature of the invention, the secondary drive means includes a sun gear journaled on the central shaft, a lock device operate to preclude rotation of the sun gear about the central axis irrespective of rotation of the central shaft, and a planet gear mounted on each subassembly axis, drivingly engaging the respective vertical part support structure, and meshing with the sun gear. This specific secondary drive arrangement provides a simple and effective means of converting the rotation of the main rack assembly into rotation of the secondary rack assemblies.
According to a further feature of the invention, the painting apparatus further includes a carriage movable along a path to a paint application station and means at the paint application station to halt the carriage at the station; the main rack is mounted on the carriage for rotation about the central axis; and the drive means includes a power device at the paint application station operative to engage and rotate the main rack about the central axis and thereby rotate the rack subassemblies about their respective subassembly axes. This arrangement facilitates movement of the rack assembly along a paint apparatus path and further facilitates compound rotation of the rack assembly as the rack assembly arrives at the paint application station.
According to a further feature of the invention, the main rack comprises a central shaft mounted for rotation about the central axis; the power device includes a driving wheel; and the drive means further includes a driven wheel fixedly mounted on the central shaft and engageable with the driving wheel. This arrangement, in combination with the previously described secondary drive means, allows the power device located at the paint application station to readily drive both the main rack assembly as well as the secondary rack assemblies whereby to achieve compound rotation of the parts to be painted and thereby achieve effective painting of the parts.
According to a further feature of the invention, the painting apparatus further includes a track structure defining the path extending to the paint application station; a load station and an unload station positioned at spaced locations along the path; a paint spray apparatus positioned at the paint application station; means for moving the carriage along the path between the load station, the paint application station, and the unload station; means for halting the carriage at the paint application station; and means for initiating the operation of the paint spray apparatus in response to halting of the carriage at the paint application station. With this arrangement, the power device positioned at the paint application station is operative with the carriage halted at the paint application station, and simultaneous with the operation of the paint spray apparatus, to spin the main rack about the central axis while simultaneously spinning each of the rack subassemblies about their respective subassembly axes.
Other objects, advantages and applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawings.